Hey guys. I'm constantly modifying my system and am now considering my first modular PSU and I have a few questions. I'm involved in several hardware oriented forums but this one seems to have the most knowledgable and experienced users so I'm asking here.
I've read some bad things about fluctuations in the rails using a modular, anything to this? certain brands worst then others? are they all like this? or is this just bull, or old news that no longer applies?
Secondly, I'm guessing my system is pretty power hungry...I'll list components at the end so what wattage should I aim for if I do get modular.
Is there anything I should know before making this jump?
Should I avoid this jump at the moment, and if so why?
Thanks in advance, I appreciate any and all comments and info on this. I would hate to damage something from it.

System specs:
Asus M4A79 Deluxe
940BE
4x2gb Mushkin (996587)
Sapphire Radeon 5850
Xfi fatal1ty champion series
1tb black edition HDD
640gb blue HDD
2x LG 22x dvd-rw's
Hauppauge 950q tv tuner
Antec Multimedia station premiere deluxe
USB keyboard/mouse (wave keyboard and a g9 mouse)
There are several USB devices that plugged in and unplugged depending on what I'm doing, like an external HD bay and a logitech gamepad and a G13 gameboard I rarely ever use and a guitar for guitar hero, I generally unplug these things when I'm not using them, but that means at least one is plugged in most of the time.
I do intend to get another 5850 in the future, hopefully sooner then later.
I think thats it